(1) Field of the Invention
The present invention generally relates to enzyme assays. More specifically, the invention is directed to novel assays for acetyltransferases and acetyltransferase substrates.
(2) Description of the Related Art
References Cited                Polevoda and Sherman, 2003, J. Mol. Biol. 325:595-622.        Roth et al., 2001, Annu. Rev. Biochem. 70:81-120.        
Acetyltransferases are enzymes that catalyze the transfer of the acetyl moiety from acetyl-CoA to their cognate substrates. These can be small molecule metabolites, antibiotics or proteins. The reaction mechanism can occur in two different ways: the direct transfer of the acetyl group from acetyl-CoA to the substrate, or initial transfer of the acetyl group from acetyl-CoA to an enzyme group on the acetyltransferase to generate the acetyl-enzyme, and subsequent transfer of the acetyl group from the acetyl-enzyme to the substrate. Both of these mechanisms have been demonstrated.
The N-acetylation of proteins by acetyltransferases is a rapidly developing area of cell signaling and regulation. These reactions are important in lifespan, transcriptional regulation, protein stability and drug resistance. Although rapid progress has been made in certain areas, the complete complement of substrates or targets for both procaryotic and eucaryotic acetyltransferases is presently unknown. In particular, bacterial genomes contain many open reading frames identified as members of the GNAT family of N-acetyltransferases (between 18 and 60, depending on the organism).
Improved methods for isolating and identifying acetyltransferases and acetyltransferase substrates are thus needed. The present invention satisfies that need.